Wired or wireless in-ear speakers (e.g., earbuds) deliver sounds to one or more ears of a user (also referred to here as a listener or wearer) of such an in-ear speaker. One type of in-ear speaker is designed to be closely coupled to a user's ear canal, referred to as an “insertable in-ear speaker”. This type in-ear speaker can be placed inside a concha at the entrance of the user's ear canal or can be inserted into the ear canal to block its entrance.
Generally there are two mutually exclusive types of insertable in-ear speakers, which are as follows: (i) an insertable in-ear speaker that fully seals an ear canal (hereinafter “sealable insertable in-ear speakers”); and (ii) an insertable in-ear speaker that is intentionally designed to allow some sounds from the ambient environment to leak into the user's ear canal during use (hereinafter “leaky insertable in-ear speakers”). Leaky insertable in-ear speakers provide better audio transparency than sealable insertable in-ear speakers. Nevertheless, sounds from the ambient environment may be unwanted to a user. To avoid this scenario, sealable insertable in-ear speakers may be used by the user. Sealable insertable in-ear speakers have some shortcomings. Users of these types of in-ear speakers can be subjected to unwanted sounds resulting from an occlusion effect (OE) during use (e.g., during telephone calls, while running, etc.). Also, a sealable insertable in-ear speaker can prevent its user from perceiving sounds from the ambient environment.